Juice alternatives for flush mixes

I know that folks have mentioned different juices that they've used in their flushes, but I just don't have much time to search back through all the posts.

Is there some way to get 6 cups (for two people) of juice without having to hand squeeze over a dozen grapefruits? It took almost an hour the last time using one of those cute little hand juicer sqeezer things and I thought my arms were going to fall off, not to mention the mess on the counter. Can we use already squeezed juice? I don't have the $$ to get a juicer right now (but we want one) and we know that it takes fresh juice to mix the ES and the oil propperly.

Sorry I haven't been around lately, please forgive me. Btween job, ministry and life I've been one busy guy these past several weeks.

Your friend and fellow flushing health nut,
Tim Tweet